Resistance of Gram-Negative Bacilli to Antimicrobials

Bradford, Patricia A.; Dean, Charles R.

doi:10.1007/978-0-387-72418-8_4

Cited by 3 publications

(3 citation statements)

References 430 publications

(465 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…At the end of exposure to GW, viability of both the control and the test groups was determined by using the Live/Dead BacLight® kit (L-7012; Molecular Probes, Salmonella fitness and pathogenicity under groundwater environments with residual antibiotics 3 Trakya Univ J Nat Sci, 20(1): [1][2][3][4][5][6][7][8]2019 Eugene, OR) according to the manufacturer's directions. Direct counting of the stained live and dead cells was done using an inverted microscope (IX70; Olympus, Japan) operated under red/green fluorescence filter set (Chroma Technology Corp., Brattleboro, VT).…”

Section: Cell Viability Analysismentioning

confidence: 99%

“…It has been previously documented that working mechanisms of these bacterial efflux pumps are directly and/or indirectly linked to the ionic components in the external environment. For example, the insertion of aminoglycosides into bacterial LPS (Bradford 2008) follows a proton gradient (energy) dependent transport across the cytoplasmic membrane. Additionally, a tetracycline efflux pump system is induced under the presence of Mg 2+ in the external environment (Roberts 1996, Orth et al 2000, which results in the excretion of the antibiotic in an energy-dependent manner with proton exchange for a tetracycline-cation complex (Yamaguchi et al 1993).…”

Section: Introductionmentioning

confidence: 99%

“…Another unknown issue with the ion-rich nature of groundwater systems is how bacterial efflux pumps are affected with respect to antimicrobial resistance, especially against aminoglyglycosides (Bradford 2008), tetracyclines (Chopra & Roberts 2001) and quinolones (Poole 2000). It has been previously documented that working mechanisms of these bacterial efflux pumps are directly and/or indirectly linked to the ionic components in the external environment.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

FITNESS AND PATHOGENICITY OF OUTBREAK CAUSING Salmonella UPON SHORT-TERM EXPOSURE TO GROUNDWATER WITH RESIDUAL ANTIBIOTICS

Haznedaroğlu

2019

Trakya University Journal of Natural Sciences

View full text Add to dashboard Cite

The changes in survival and pathogenicity of three Salmonella enterica subsp. enterica serotypes upon short term exposure to groundwater with residual antibiotics have been studied in relationship to overall microbial fitness. A wild type flagellated Salmonella enterica ser. Typhimurium outbreak strain, a mutant Salmonella enterica ser. Typhimurium strain, and a wild type avian disease-causing Salmonella enterica ser. Pullorum strain were exposed to a range of ionic strength (3-30 mM) groundwater with residual antibiotics for 6-24 hours. Exposed organisms' pathogenicity was tested in vitro exposure to a human epithelial cell line (HEp2). Resistance profiles against 10 common antibiotics were also tested and compared to unexposed controls. Results show minor antibiotic resistance changes for S. enterica ser. Typhimurium strains in response to some antibiotic classes mediated with active efflux pumps. This trend was not observed for S. enterica ser. Pullorum, suggesting that resistance found in groundwater exposed organisms might be strain-dependent. In vitro epithelial cell invasion assays showed bacterial invasion of HEp2 cells initially decreases with time and increases after 24 hours. It is concluded that S. enterica serotypes reaching groundwater environments in the presence of residual antibiotics may exhibit increased levels of pathogenicity, strain-dependent resistance to antibiotics, and sustained levels of viability.Özet: Bu çalışmada kalıntı miktarda antibiyotik içeren yeraltı sularına kısa süreli maruz bırakılan üç Salmonella enterica subsp. enterica serotipinin hastalık yapıcı özelliklerindeki değişiklikler ve hayatta kalabilme seviyeleri genel mikrobiyel fitnes çerçevesinde incelenmiştir. Serotipler gerçek bir salgından izole edilen kamçılı doğal fenotip Salmonella enterica ser. Typhimurium, kamçısı fonksiyonel olmayan bir başka Salmonella enterica ser. Typhimurium suşu ve kuş türlerinde salgına yol açan doğal fenotip Salmonella enterica ser. Pullorum'dan oluşup, iyon şiddeti değişken (3-30 mM) ve kalıntı miktarda antibiyotik içeren yeraltı suyuna 6-24 saat sürecince maruz bırakılmıştır. Serotiplerin hastalık yapıcı özellikleri in vitro koşullarda HEp2 türü insan epitel hücre kültürleri kullanılarak ölçülmüştür. Antibiyotik direnç seviyeleri ise yaygın kullanılan 10 antibitiyotiğe karşı disk difüzyon testi yardımıyla belirlenmiştir. Deneyler sonucunda S. enterica ser. Typhimurium suşlarında antibiyotik direnç seviyelerinde az miktarda artış gözlenirken S. enterica ser. Pullorum suşunda değişiklik gözlenmemiştir. In vitro deneylerde ise suşların HEp2 hücrelerini enfekte etmeleri zamanla önce azalmış, 24 saatlik dilim sonunda ise artmıştır. Sonuç olarak, kalıtsal antibiyotik içeren yeraltı sularına temas eden S. enterica serotiplerinin hastalık yapıcı karakterlerinin arttığı, antibiyotik direnç seviyelerinin suşa bağlı olarak değişkenlik gösterirken hayatta kalma oranlarının yüksek olduğu gözlenmiştir.

show abstract